Half of Universe's starlight comes from young star-forming galaxies

Published: Thursday, April 9, 2009, 12:48 [IST]

Subscribe to Oneindia News

Washington, April 9 (ANI): Using a two-tonne telescope, scientists from the University of Toronto and the University of British Columbia (UBC) have found that half of the starlight of the Universe comes from young, star-forming galaxies several billion light years away.

The finding was a result of a two-year analysis of data from the Balloon-borne Large-Aperture Sub-millimeter Telescope (BLAST) project.

"While those familiar optical images of the night sky contain many fascinating and beautiful objects, they are missing half of the picture in describing the cosmic history of star formation," said UBC Astronomy Professor Douglas Scott.

"Stars are born in clouds of gas and dust," said Barth Netterfield, a cosmologist in the Department of Astronomy and Astrophysics at U of T.

"The dust absorbs the starlight, hiding the young stars from view. The brightest stars in the Universe are also the shortest lived and many never leave their stellar nursery. However, the warmed dust emits light at far-infrared and submillimetre wavelengths - invisible to the human eye, but visible to the sensitive thermo-detectors on BLAST," he added.

According to UBC Professor Mark Halpern, part of the UBC team that also includes post-doctoral fellows Ed Chapin and Gaelen Marsden, "The history of star formation in the universe is written out in our data. It is beautiful. And it is just a taste of things to come."

The study combines BLAST submillimetre observations at wavelengths around 0.3 mm - between infrared and microwave wavelengths - with data at much shorter infrared wavelengths from NASA's Spitzer Space Telescope.

It confirmed that all of the Far Infrared Background comes from individual distant galaxies, answering a decade-old question of the radiation's origin.

"BLAST has given us a new view of the Universe," said Netterfield, whose U of T colleagues on the project include department chair Peter G. Martin and graduate students Marco P. Viero, Donald V. Wiebe (now a post-doc at UBC) and Enzo Pascale (now a faculty member at Cardiff University).

"The data we collected enable us to make discoveries in topics ranging from the formation of stars to the evolution of distant galaxies," he added. (ANI)